Means for pumping liquid fuels



July 2, 1929- J. F. DENISON ET A1. 1,719,501

MEANS FOR PUMPING LIQUID FUELS Filed Feb. 16, 4192,7

ano: nu,

Patented July 2, 1929.

UNITED STATES PATENT OFFICE'.

JULIAN l'. DENISON AND HARRY F. HOBSON, 0F NEW HAVEN, CONNECTICUT; SAID DENISON ASSIG'NOB TO SAID HOBSON.

MEAN FDR PUMPING LIQUID FUELS.

Application led February 16, 19.27. Serial No. 168,626.

Our invention relates to a fuel feeding system, and more es ecially to one suitable for use in feeding uel to the burner of a heating system.

I Three types of fuel feeding devices are commonly used in heating systems; one having a pump for feedin oil under high pressure, which is sprayer? into the burner, entr'aining sufficient air as it passes in to form a combustible mixture; a second in which an air pump forces a blast of air over an oil nozzle to entrain sufficient oil to'form the combustible mixture; and a third in which both air and oil are forced in under presll sure. The third system is generally considered to be the most eiiicient and in these systems an oil pump of the geared piston type is commonly used for the fuel oil, while a rotary fan blower furnishes a supply of air. A single motor is generell used to operate both the oil pum blower, entailing the use o a complicated transmission, and also' lthe fan blower must be provided with a lubricating system. As one of the main objects of our invention we contemplate a system in which a single pump may be used to pump both air and oil, thus eliminating the transmission ordinarily necessary, and since oil is continually passing through the pum no special oiling means has' to be provid There is considerable danger from fire in oil heating systems, owing to the liability of oil to accumulate in the fire box and on the basement floor when the burner is out by siphoning from the main supplv tank and flow from the auxiliar tank in the basement, as well as from t e associated mechanism. Elaborate means Iare usuall provided to prevent this flow of oil. As a urtlier object of our invention we contemplate a system in which there is no tendency of the oil to flow when the burner is out and no special means is necessary to prevent siphoning.

A still further ob'ect of our invention is to provide a system avi no open connections or venter within thenguilding in which the device' is located.

Another object of our invention is to provide an im roved means for controlling the flow of oil 1n the stem An additional ject of our invention is to brin the air and oil into intimate contact be ore they are introduced into the caran the air 7.

bureter or mixing device, in order that the air may be saturated with oil vapors.

To these and other ends, our invention consists in the novel features and combinations of parts to be hereinafter described and claimed.

In the drawings,

Fig. 1 is a general view of our improved fuel feeding system;

Fig. 2 is an enlarged view, shown in section, of a float and associated mechanism for controlling the flow of oil in the system; and

Fig. 3 is an enlarged view of a nozzle for spraying the air and oil into the burner.V

Referring to the drawings in which we have illustrated our invention b showing a preferred embodiment thereof, tlie reference numeral 3 indicates in general a tank, composed of an upstanding tubular body 4, ad- ]ustably supported on avbase 5, and caps 6 and On the upper end of the tank 3 and supported` by the cap 7, is a horizontal platform 8, having on one end a pump 9, which may be of any well known type, herein shown as a rotary pump, having a substantially cylindrical casino" 10, an 'eccentric rotor 11, mountedlwitliin the casing and in contact with the wall thereof between the inlet and outlet openin and blades 12 held against the walls of t e casing by centrifugal force, springs, or any other suitable means. Aa 85 'shown in the drawings, one end cover of the pump is removed to show the interior arrangement. The outlet 13 of the pump 9 is connected to the tank 3 by the pipe 14, secured in the cap 7. A pipe 15 is connected to the intake 16 of the pump 9 and by means of a T-fitting 17 is connected to a pipe 18 which leads to a supply tank for liquid fuel. Connected to the other opening of the T-fitting 17 is an air ipe 19, which preferably leads to the outsi e of the building, and to an elevated position. Connected to the bottom of the tank 3 is an oil discharge line 20, having an upstanding portion 21 and a horizontal portion 22, while at the upper end of the tank 8 is an air discharge pi e 28 connected by a pipe 24 to a nozzle 5 to which the oil supply pipe 22 is also connected. On or near the nozzle is a valve 26 for controlling the flow of oil throu h the nozzle, while a valve 27 controls the ow of air through the pipe 24. Connected the pipe 23 is an upstanding pipe 28, having at its upper end a pressure relief valve 29, which may be of any well known type, not shown herein in detail. The exhaust opening of the pressure relief valve is connected by a pipe to the pipe 19. Inside the tank 3 is a vertically movable float 31, having. a.

rod 32 secured thereto and extending upwardly therefrom and received within a pipe 33. Mounted on the pipe 33 is a check valve 34 having the customary ball valve 35, held to seat .by the spring 36. From the check valve 34 a pipe 37 extends uplwardly and is connected to the pipe 18 by t e T-fitting 38.

On the outside of the tubular member 4 is provided an oil level indicating gauge 39,.

which may be of any well known type. In the air line 15 a valve 40 is provided forcontrolling the amount of air passing to the' by means of a belt 46 and receiving power through wires 47 which are in series, with a thermostatically operated switch 48, which may be of any desirable type, not shown in detail herein.

The nozzle 25 may be of 'any desirable type and herein is shown as consisting of a tubular body portion 51having one end secured in a T-tting 52. A plug 53 is secured in the T-fitting opposite the member 51 and in the plug is mounted an oil pipe 54 connected to t e pipe 22 by a union 55. The air pipe 24 is connected to the remaining .opening in the fitting.

which is at one end connected to the pipe 54 and at the other end has an extension 57. Secured on the tubular member 51 at the same end as oil n'ozzle 56 is a thimble 58, having a hole in its end surrounding the member 57 and providing therewith an annular opening for the assage of air, notches 59 being provided in t e member 56 so that air may ass therethrou h.

A strainer 49 is provi ed in the line 15 to prevent the introduction of foreign matter into the pump 9 and also assists in bringing the oil and air into close contact. The strainer may be of any well known type and is not shown here in detail.

The adjustable base 5 of the tank 3 is made in two parts, as shown, which are secured together and clamped on tube 4 by means of bolts 50. Suitable provision is made in the base 5 for clearing the oil level indicating glass 39 upon the base being adjusted to a higher osition on the tank 3 than that shown in t e drawings.

In operation, assuming the temperature in Mounted on-the plat- In the opposite end of the mem' *ber 51 from the T-fitting is an oil nozzle 56,

the rooms of the house to be low enough so that the thermostat 48 closes the switch in the line 47, the electric motor being supplied with power drives the pump 9 which, through the suction created in the line 15, draws in oil from the line 18 and air from the line 19, in proper proportions, through the regulation of valves 40 and 41. The air being brought into intimate contact with the oil becomes saturated with oil vapors and both air and oil pass out of the discharge line .14 of the pump 9 to the tank 3 where they separate, the oil falling to the bottom of the tank and the air collecting at the top of the tank under pressure. The, air pressure in the tank 3 forces the Oil out through the lines 20, 21 and 22 to the nozzle 25, where it passes into the burner. At the same time compressed air from the tank 3 passes through the pipes 23 and 24 to the ,nozzle 25 where it mingles with the oil being sprayed into the burner to form a combustible mixture.

As the pump continues to feed oil into the tank 3, the level in the tank 3 rises, carrying the float 31 with it to the point where the rod 32 unseats the valve 35 permitting air to pass from the tank 3 through the pipes 33 and 37 to the oil line 18. The introduction of air under pressure to the oil line 18 breaks the vacuum produced in this line by the pump 9 and stops the further flow of oil to the ump. Air now passes from line 18 and is ed to the tank 3. When the liquid level in the tank 3 falls to its normal height the float 31 drops and the valve 35 becomes seated so that oil again flows to the pump 9.

The normal -pressure that we have found desirable for use in our system is four pounds. When the pressure in tank 3 increases beyond this point, the pressure relief valve 29 being in communication with tank 3, through pipes 23 and 28, opens, allowing the excessive pressure to pass off through pipes 30 and 19 to the outside of the building, it being undesirable that this air should be exhausted within the building, due to the oil vapors carried thereby.

By providing an upstanding portion in the oil discharge line 20 and the horizontal ortion 22 above the normal level of the oil 1n the tank 3 we are able to overcome any possibility of the oil passing from tank 3, into the burner after the motor has stopped. When the motor stops and with it the pump 9, the air in tank 3 escapes by way of nozzle 25 and the pressure within the tank is reduced to atmospheric pressure, whereu on any oil in the nozzle and pipe 22 will ow back to tank 3, thus preventing an dripping of oil into the furnace from nozz e 25. Although the pipe 22 and nozzle 25 are shown at a considerable distance above the basement floor it will be readily understood that the tank 3 may be disposed, fo'r the greater part, below the level of the basement floor in a pit and the base 5 is made adjustable for this purpose being secured on the tank in any desired position by the bolts provided.

It will be noted that the air pipe 19 by its connection with the oil pipe 18 provides a vent for the latter when the pump is not operated. This vent by introducing air into the oil line effectively prevents any siphoning of oil into the system, it being understood that the pipe 18 is positioned above the level of oil 1n the main supply tank.

There being no open connections or vents in our system within the 'building in which it is placed there is very little likelihood of any leakage and no danger from fire or explosions.

While we have shown and described some embodiments of our invention, it will be unf derstood that it is not to be limited to all the details shown, but is capable of modification and variation within the spirit of the invention and within the scope of the appended claims.

What we claim is 1. In a fuel feeding system, a main supply tank for liquid fuel, an auxiliary tank, a combined air and liquid fuel pump, a connection between the outlet of said pump and Said auxiliary tank, a connection between the inlet of said pump and said main tank, said last named connection permitting the free flow of liquid fuel from. said tank to said pump at all times, and a'permanently open air inletl in said last named connection, said air inlet being at the highest point of said connection.

2. In a fuel feeding system, a main supply tank for liquid fuel, an auxiliary tank, a cpmbined air and liquid fuel pump, a connection between the outlet of said pump and said auxiliary tank, a connection between the inlet of said pump and said main tank, said last named connection ermitting the flow of liquid fuel frorn saidp main tank to the pump at all times, a permanently open air inlet in said last named connection, and means for interrupting the flow of oil through the connection to the main tank when the liquid level in the auxiliary tank reaches a predetermined height.

3. In a fuel feeding system, a main supply tank for liquid fuel, an`auxiliary tank, a combined air and liquid fuel ypump, a connection between the outlet of said pump and said auxiliary tank, a connection between the inlet of said pump and said main tank, said last named connection permitting the flow of liquid fuel from said main tank to the ump at all times, a permanently open air in et in said last named connection, and means for interrupting the flow of oil through the connection to the main tank when the liquid level in the auxiliary tank reaches a predetermined height, said means for controlling the flow of oil through the connection between the main tank and the pump comprising a connection between the upper part of the auxiliary tank and the connection between the inlet of the pump and the main supply tank, a valve in said connection with the top of the auxiliary tank, and a float for unseating said valve when the oil level in 1the 1auxiliary tank reaches a predetermined eve 4. In a fuel feeding system, a main supply tank for liquid fuel, an auxiliary tank, a combined air and liquid fuel pump, a connection between the outlet of said pump and said auxiliar tank, a connection between the inlet of sai pump and said main tank, a permanently open air inlet in said last named connection, a connection between the top of Asaid auxiliary tank and the connection between the inlet of the pump and the main tank, and float controlled means for permitting the passage of air from the auxiliary tank through the connection between the top of the tank and the connection between the pump and main supply tank when the liquid fuel level in the auxiliary tank reaches a predetermined level, said float controlled means including a valve in the connection with the top of the auxiliary tank and a float in the auxiliary tank, said float having a cross-sectional area but slightly less than the, cross-sectional area of the interior of the tank whereby the float is sensitive to slight changes in the amount of liquid fuel contained in the tank. In witness whereof, we have hereunto set our hands this 14th day of February, 1927.

JULIAN F. DENISON. HARRY F. HOBSON. 

